Water cooling system for outboard motors



Nov. 4, 1952 E. c. KIEKHAE'FER 2,616,386

WATER COOLING SYSTEM FOR OUTBOARD MOTORS Filed July 29, 1948 3 Sheets-Sheet 1 E. C. KIEKHAEFER WATER COOLING SYSTEM FOR OUTBOARD MOTORS Filed July 29, 1948 Nov. 4, 1952 5 Sheets-Sheet 2 P k 1 w VENTOR eiidefi'n W M/(uz JZIarnez s Nov. 4, 1952 E. c. KIEKHAEFER' 2,616,386

WATER COOLING SYSTEM FOR OUTBOARD MOTORS Filed July 29, 1948 s Sheets-Sheet 3 J/lorn er s' Patented Nov. 4, 1952 Elmer Carl Kiekhaefer, Qedarbnrg, Application 'J uly'29, 1914-8, fielfial Njo. 4132,63

13 Claims. 1

This invention relates to outboard motors and 'particularly to details of construction of the water inlet ports therefor.

A principal object of the invention is to increase the efiicien-cy of the water cooling system ofan outboard motor.

Another object of the invention is to supplement the usual water circulating means of the water cooling system of an outboard motor for the increased efiiciency of operation of the motor.

Another object is to reduce the machining operations required in the construction of the gear case of an outboard motor housing the water circulating means.

' Another object is to reduce the frictional resistance of the water entering the inlet ports of the water circulating means in the gear case of an-outboard motor. I These and other objects and advantages will be more fully set forth in the following description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

In-the drawings:

Figure 1 is a side elevation of an outboard motor;

Fig. '2 is a detailed view in side elevation of the lower gear housing of the motor;

'Fig. 3 is a front elevation of the gear housing of Fig. 2;

Fig. 4 is an enlarged vertical sectional view of the gear housing taken along its longitudinal center line;

Fig. 5 is an enlarged view in cross-section through the gear housing on lines 5 5 o-f Fig. -2; Fig.6 is a sectional view througha part of the gear housing showing an alternate embodiment of the invention;

Fig. 7 is a side elevation of the gear housing shown in Fig. 6 with parts broken away;

Fig. 8 is a view similar to Fig. 2 showing another embodiment of the invention; and

"similar to that disclosed and claimed in my copending application entitled Outboard Motor, Serial No. 747,443 and filed May 12, 1947, and which issued April 17, 1951, to U. S. Patent No.

2.549.477 entitled Gear Case Unit forbutboard 2 I Matc -"and also '-U 8. Patent No. 2,549,484 rentitled Underwater Gear Units f-or Outboard -M'otors granted the present inventor April 11 7, 1951.

The housing com-prises the upper .narrow' bo'dy or strut "-7, the gear case 8 a'nd ithe s'kegill e'xtending therebeneaith to proteot'the zprope'ller il-ffl mounted at the rear end of the gear case.

The lowerhousing- 4 is fabricated by die casting and is provided with a number of cored openings l I, 2 and l -3 extending {from th :upper end which fits the corresponding lower surface-of the drive shaft housing 3. Two cored holes l l near the leading and trailingedgesof the housing receive 'tl-ie 'bolts 5 securing housings- 3 and 4 case and a large main bearing 2-0 fitting within the opening supports the sue-a. The forWard end of the gear case is closed by a bearing packing ring -2 l on shaft =l-8 iu'st in ba'ck-of hearing 20.

The "outer surface of gear case 8 is tapered :at the forward end and merges "with the forward leading edge of the lower housing. The :rear end of the case projects :beyond the trailing edge.o,f the housing and encloses the :water' p'ump 2-2 which is mounted-on shaft-l 81in backof: the;packing ring seal 21. A threaded circular rear-end plate 23 closes the cored openin H5 and serves to secure the propeller assemblyiwithin the gear case.

The passageway =24 is formed by drilling the casting from cored :opening ZIBEto the vertical opening '14 and provides for communication between the water pipe l5 and theoutl'etport fi ofthewater'pumpfl.

Any type of plunger "OI'fIOtEi-ly pump maybe employed, the pump illustrated-being mounted-"on shaft 18 as described similar to-that disclos-ed and claimed in my copending application entitled "W'ater Pump for Outboard Motors) Serial No.

637,523, filed December 28', 1945; now U. s. Patent No. 2,493,148'dated January 3, 1950.

The'inlet port 26-ofgpump 22 is'spacedoppositelyo'f port 25 and registers with holes in the may of 'the'gear housing through which the water passing the housing is admitted for circulation by pump 2-2 through {the cooling system of the motor.

In the embodiment of the invention shown in Figs. 1 through 5 a plurality of small drilled holes 21 are provided as the water inlet, and the approach to each hole 21 is formed by the longitudinal tapering grooves 28 preferably cast in the outer surface of the gear case. Each hole opens forwardly at an angle and into a groove 28 so that a frontal area is presented in effect to scoop the water passing the gear case 8 into the holes. The holes 21 are arranged as shown so that the grooves for each do not overlap the grooves of other holes.

The chamfered approach to each hole provides for entry of the water into the hole with a minimum of eddy. The sharp opposite edge sets up a minimum of turbulence in the water passing the edge and approaching the following hole.

In the embodiment of the invention shown in Figs. 6 and '7 embodying a similar principle of operation the slots 29 are chamfered along the outer front edge as at 30. The chamfers extend to the opposite edges of the adjacent slots so that a sharp edge is formed providing a sawtooth construction as shown. The metal between slots 29 is built up like a lip so that each rearward slot opens slightly outwardly of the preceding slot. Each slot thereby has an equal area facing into the stream of water. The slots may be formed in the casting of the housing 4 thereby reducing machining costs.

In the embodiment of Figs. 8 and 9 a number of parallel spaced flutes 3! or channels are preferably cast in the outer body of the gear case 8 and extend therein forwardly a substantial distance from their respective slots 29. Each fiute terminating at the forward edge of a slot 29 provides a substantial frontal area on the opposite side of the slot facing into the stream of Water. At least one flute is employed for each slot and flutes for the second and following slots cross the preceding slots as shown in the drawings so that the metal between the slots need a substantial distance rearwardly of the tapered forward end thereof assures a supply of water under such pressure at all times including periods of operation near the surface of the water. In operating fully submerged, the strut 1 tends to cause interfering currents over the upper side of the gear case which are avoided by placing the inlet openings in the underside thereof and nearer the skeg 9 which is narrow and causes no such interference. In operating partially submerged, the water passing over the gear case has a tendency to break away from the upper half of the body of the gear case. The ports thus allow the motor to be operated with gear case 8 located near the surface of the water and assure a supply of water .at all times for cooling of the engine. Furthermore, location of the ports near and to one side of the skeg avoids danger from possible stoppage by foreign matter which may become lodged on the front nose or skeg. The design of the ports adds 4 little or nothing to the die costs or cost of manufacture of the housing.

Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim:

1. In a gear housing for an outboard motor having a water cooling circulation system, water inlet ports for said system in the submerged portion of said housing and cast integrally therewith comprising a number of ports of at least one dimension to preclude relatively larger foreign particles of a size usually encountered in outboard motor operation from passing therethrough, and separate chamfered approaches formed in the exterior surface of said housing terminating with each of said ports whereby the eificiency of said ports is substantially maintained under all conditions.

2. In a gear housing for an outboard motor having a water cooling system, water inlet ports for said system in the submerged portion of said housing comprising a plurality of ports, and channels formed in the outer body of said housing in the direction of flow past said housing, said channels terminating with each port and each port having a rear wall exposed directly to a predetermined separate part of the flow stream to guide the water into and through the port with a minimum of interference with the fiow stream.

3. In an outboard motor having a water cooling system and a submerged member with inlet ports for the cooling system, comprising a plurality of parallel slots spaced in the direction of the flow of water and disposed laterally of the flow of water, the approach edges of said ports as defined by said housing being chamfered and the corresponding opposite edge of each slot extending outwardly beyond the corresponding edge of the preceding slot whereby the frontal area of each slot is substantially equal and the flow of water into the slots around the chamfered edges is subject to a minimum of turbulence and eddy losses.

4. In an outboard motor, an underwater gear unit having a streamlined housing including an enlarged body portion comprising the gear case, said gear case being exteriorly of substantially circular transverse section rearwardlyof the housing and tapering forwardly and merging with the forward edge of the housing, and a water cooling circulation system for the motor having water inlet ports in said gear case toward the rear thereof, and separate chamfered approaches to each of said ports formed in the outer surface of said case and extending toward the tapered forward end thereof whereby in the operation of the motor the water stream passes over the gear case in advance of the ports with a minimum of turbulenceand into said ports without interference.

5. In an outboard motor, an underwater gear unit having a streamlined housing including an enlarged body portion comprising the gear case, said gear case being exteriorly of substantially circular transverse section rearwardly of the housing and tapering forwardly and merging with the forward edge of the housing, and a water cooling circulation system'for the motor having water inlet ports in said gear case toward the rear thereof, and separate chamfered approaches to each of said ports formed in the outer surface of said case and extending toward the tapered forward end thereof whereby in the operation of the motor the water stream passes over the gear case in advance of the ports with a minimum of turbulence and into said ports without interference, the portions of said gear case defining the rear walls of each of said ports being exposed to separate and equal parts of the water stream.

6. In an outboard motor, an underwater gear unit having a streamlined housing including an enlarged gear case, said gear case exteriorly being of substantially circular transverse section rearwardly of the housing and tapering forwardly and merging with the forward edge of the housing, and a water cooling circulation system for the motor having water inlet ports in said gear case near the rear thereof, said ports comprising slots forming narrow openings extending transversely of the flow stream, at least a portion of the rear wall of each slot being exposed to adjacent separate parts of the flow stream, and the forward wall of each slot being chamfered at the opening to provide individual approaches to each port.

7. In an underwater gear housing for an outboard motor having a water coolant circulating system, water inlet ports opening from the outside of said housing to said system for delivery of water thereto, said ports comprising a plurality of comparatively small bores adapted to exclude relatively larger foreign objects encountered in outboard motor operation while providing the required delivery of water for said system, and separate chamfered approaches formed in the exterior portion of said housing in advance of each respective port with respect to the direction of flow of water and terminating with each respective port.

8. In an underwater gear housing for an outboard motor having a water coolant circulating system, water inlet ports opening from the outside of said housing to said system for delivery of water thereto, said ports comprising a plurality of comparatively small bores adapted to exclude relatively larger foreign objects encountered in outboard motor operation while providing the required delivery of water for said system, and separate chamfered approaches formed in the exterior portion of said housing in advance of each respective port with respect to the direction of flow of water, the portions of said gear housing defining the rear walls of each said ports being exposed by the approaches formed in the exterior portion of said housing to separate water streams.

9. In a gear housing for an outboard motor having a water cooling circulation system, water inlet ports for said system comprising a number of slots in the submerged portion of said housing and opening into said system, said slots being relatively spaced in the direction of water flow and extending normal to the water flow, the portion of said housing defining the outer forward edge of each slot being chamfered for the indirect entrance of the water into the respective slot and a portion of said housing defining the rear wall of said slot being exposed directly to the flow of water past said housing.

10. In an outboard motor, an engine, a lower gear housing normally disposed at least partially under water, a water coolant circulatory system for said engine and including a supply passage from said housing, said housing including a streamlined horizontally tapered portion for receiving and enclosing the gears and a supporting strut upwardly thereof, and a plurality of inlet openings to said passage in the underside 6 of the tapered portion of said housing and near the larger section thereof, said openings being spaced laterally respecting the relative direction of movement of the water to receive separately the water passing the underside of said tapered portion.

11. In a gear housing for outboard motors hav= ing a water cooling circulation system, a cast member having an upper supporting strut and a lower enlarged body with a gear chamber formed therein and having tapered, streamlined outer dimensions to enforce the laminar flow of water therebeneath with a minimum of resistance, and a plurality of inlet ports for said circulation system opening into the larger section of said body disposed and spaced laterally respecting said laminar flow to receive separate equally channeled streams of water passing the underside of said body remotely of said strut and in a direction parallel to the direction of movement of said member.

12. In a gear housing for outboard motors having a water cooling circulation system, a cast vmember having an outer streamlined body with a chamber formed therein, a water circulating pump disposed within said chamber and operatively connected to said circulation system, a plurality of inlet ports in the underside of said streamlined body opening directly to said pump, said ports being spaced laterally respecting the direction of approach of the water to receive separate streams of water passing the underside of said body, and a strut supporting said cast member and joined thereto remotely of said ports.

13. In a gear housing for outboard motors having a water cooling circulation system, a member having a lower narrow projecting skeg adapted to protect the propeller of the outboard motor against damage and a larger upper supporting strut, said member having a gear chamber formed therein and of tapered, streamlined outer dimensions to enforce the laminar flow of water streamlines over said member between said strut and said skeg, and at least one inlet port for said circulation system opening into the larger section of said member, said port being disposed adjacent to said skeg and remote from said strut and the forward end of the housing to receive the water passing beneath said member so as to be subject to the least interference by foreign matter and eddy currents passing said port.

E. CARL KIEKHAEFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,579,834 Pierce Apr. 6, 1926 1,641,670 French Sept. 6, 1927 1,689,962 Peck Oct. 30, 1928 1,762,957 Buehner June 10, 1930 1,893,661 Smith Jan. 10, 1933 1,910,561 Pierce May 23, 1933 1,932,523 Ingens Oct. 31, 1933 2,212,939 Irgens Aug. 27, 1940 2,281,459 Scott-Paine Apr. 28, 1942 2,477,637 Mercier Aug. 2, 1949 FOREIGN PATENTS Number Country Date 710,780 Germany Sept. 20, 1941 

